Mars rover team members have begun a new phase of testing at JPL -- using longer-duration experiments -- in their preparations for driving Spirit again on Mars.

They have completed assessments of individual maneuvers, using the test rover in a box of sloped, soft soil that simulates conditions at the patch of Martian ground called "Troy," where Spirit's wheels have dug themselves hub-deep. Tests beginning today are using combinations of the individual maneuvers and longer-duration drives. These tests will evaluate a full escape strategy for Spirit.

With the test rover temporarily removed from the box on Friday, July 24, the rover team members renewed the test setup. They tamped the soil in the uphill half of the box with more pressure than the soil on the downhill side. This was done to offer a closer simulation to the conditions at Troy, where Spirit's wheels have not churned up the soil as much on the uphill side.

At Troy, meanwhile, Spirit is continuing to use all of its tools to examine the environment around it.